Imaging the cytoskeleton in live Xenopus laevis embryos.

Historically, much of our understanding of actin filaments, microtubules and intermediate filaments has come from the study of fixed cells and tissues. But the cytoskeleton is inherently dynamic, and so developing the means to image it in living cells has proved crucial. Advances in confocal microscopy and fluorescent protein technologies have allowed us to dynamically image the cytoskeleton at high resolution and so learn much more about its cellular functions. However, most of this work has been performed in cultured cells, and a critical next step is to understand how the cytoskeleton functions in the context of an intact organism. We, and others, have developed methods to image the cytoskeleton in living vertebrate embryos. Here, we describe an approach to image the cytoskeleton in embryos of the frog, Xenopus laevis, using mRNA to express fluorescently tagged cytoskeletal probes and confocal microscopy to visualize their dynamic behavior.